Abstract: The present invention refers to a process for the production of paper from a suspension containing cellulosic fibres, and optionally fillers, comprising adding to the suspension at least one cationic organic polymer and an aqueous silica-containing composition comprising an anionic naphthalene sulphonate formaldehyde condensate and anionic silica-based particles, the composition having a weight ratio of naphthalene sulphonate formaldehyde condensate to silica-based particles within the range of from 0.2:1 to 99:1, and containing naphthalene sulphonate formaldehyde condensate and silica-based particles in an amount of at least 0.01% by weight, based on the total weight of the aqueous silica-containing composition, and with the proviso that the composition contains substantially no cellulose-reactive sizing agent. The invention also encompasses an aqueous silica-containing composition and a method for preparation of an aqueous silica-containing compound.

Abstract: The present invention relates to an aqueous silica-containing composition comprising an anionic organic polymer having at least one aromatic group and anionic silica-based particles. The aqueous silica-containing composition contains the anionic organic polymer having at least one aromatic group and the anionic silica-based particles in an amount of at least 0.01% by weight of the total weight of the aqueous silica-containing composition. The aqueous silica-containing composition contains substantially no cellulose-reactive sizing agent and the anionic organic polymer having at least one aromatic group is not an anionic naphthalene sulphonate formaldehyde condensate. The invention further relates to methods for the preparation of the aqueous silica-containing composition and the use of the aqueous silica-composition as a drainage and retention aid in a process for the production of paper.

Abstract: The present invention refers to a process for the production of paper from a suspension containing cellulosic fibers, and optionally fillers, comprising adding to the suspension at least one cationic organic polymer and an aqueous silica-containing composition comprising an anionic naphthalene sulphonate formaldehyde condensate and anionic silica-based particles, the composition having a weight ratio of naphthalene sulphonate formaldehyde condensate to silica-based particles within the range of from 0.2:1 to 99:1, and containing naphthalene sulphonate formaldehyde condensate and silica-based particles in an amount of at least 0.01% by weight, based on the total weight of the aqueous silica-containing composition, and with the proviso that the composition contains substantially no cellulose-reactive sizing agent. The invention also encompasses an aqueous silica-containing composition and a method for preparation of an aqueous silica-containing compound.

Abstract: The present invention relates to an aqueous silica-containing composition comprising an anionic organic polymer having at least one aromatic group and anionic aggregated or microgel formed silica-based particles. The aqueous silica-containing composition contains the anionic organic polymer having at least one aromatic group and the anionic silica-based particles in an amount of at least 0.01% by weight of the total weight of the aqueous silica-containing composition. The aqueous silica-containing composition contains substantially no cellulose-reactive sizing agent and the anionic organic polymer having at least one aromatic group is not an anionic naphthalene sulphonate formaldehyde condensate.

Abstract: An image scanner for microscopic objects. The image scanner has a microscope with a high precision computer controlled motor driven stage to provide X,Y plane displacements in order to scan microscopic objects under the microscope. There is an image sensor and a digitizer in association with the microscope to sense a horizontal image line or a two dimensional image and provide a digital representation of the line or image. A digital signal processor processes digitized signals from the sensor. There is a computer to control the mechanical and electronic scanning and to store and display information from the digital signal processor. Methods of scanning a microscopic object are also described. The methods comprise positioning the object on a motorized stage of a microscope having an image sensor in a focal plane. The object is scanned and signals received from the sensor during scanning are digitized.